The Grumman F8F Bearcat (affectionately called "Bear") was an American single-engine naval fighter aircraft of the 1940s. It went on to serve into the mid-20th Century in the United States Navy and other air forces, and would be the company's final piston engined fighter aircraft.
Designed for the interceptor fighter role, the design team's aim was to create the smallest, lightest fighter that could fit around the Pratt & Whitney R-2800 engine (carried over from the F6F Hellcat). Compared to its predecessor, the Bearcat was 20% lighter, had a 30% better rate of climb and was 50 mph (80 km/h) faster. It was also considerably smaller in size, as it was designed to be operated from small escort aircraft carriers, something the big Hellcat rarely did. Thus the F8F Bearcat was intended mainly as a replacement for the obsolete FM2 Wildcat, still the mainstay fighter of the many wartime escort carriers.
In comparison with the Vought F4U Corsair, the initial Bearcat (F8F-1) was marginally slower but was more maneuverable and climbed more quickly. Its huge 12' 4" Aero Products four-bladed propeller required a long landing gear (made even longer by the mid-fuselage position of the wing), giving the Bearcat an easily-recognized, "nose-up" profile. The hydraulically operated undercarriage used an articulated trunnion which extende the length of the oleo legs to lengthen when down; as the undercarriage retracted the legs were shortened, enabling them to fit into a wheel well which was entirely in the wing. An additional benefit of the inward retracting units was a wide track, which helped counter propeller torque on takeoff and gave the F8F good ground and carrier deck handling. . For the first time in a production Navy fighter, a bubble canopy offered 360-degree visibility.
The Bearcat concept was inspired by the early 1943 evaluation of a captured Focke-Wulf Fw 190 by Grumman test pilots and engineering staff. After flying the Fw 190, Grumman test pilot Bob Hall wrote a report directed to President Leroy Grumman, who then personally laid out the specifications for Design 58, the successor to the Hellcat. Design 58 closely emulated the design philosophy of the German fighter, although no part of the FW 190 was copied. The F8F Bearcat stemmed from Design 58  with the primary missions of outperforming highly maneuverable late-model Japanese fighter aircraft such as the A6M5 Zero. A role which later developed was that defending the fleet against incoming airborne suicide (kamikaze) attacks.
The target loaded weight of 8,750 lbs (derived from the land-based German aircraft) was essentially impossible to achieve as the structure of the new fighter had to be made strong enough for aircraft carrier landings. Structurallythe fuselage used flush riveting as well as spot welding, with a heavy gauge 302W aluminium alloy skin. Armor protection was provided for the pilot, engine and oil cooler; weight saving measures include restricting the internal fuel capacity to 160  (later 183) gallons and limiting the fixed armament to four .50 cal Browning M2/AN machine guns, two in each wing.
As a weight-saving concept the designers came up with detachable wingtips; if the g-force exceeded 7.5g then the tips would be allowed to snap off, leaving a perfectly flyable aircraft still capable of carrier landing. While this worked very well under carefully controlled conditions in flight and on the ground, in the field, where aircraft were repetitively stressed by landing on carriers and since the wings were slightly less carefully made in the factories, there was a possibility that only one wingtip would break away with the possibility of the aircraft crashing. This was replaced with an explosives system to blow the wings off together, which also worked well, however this ended when a ground technician died due to accidental triggering. In the end the wings were reinforced and the aircraft limited to 7.5g.
Grumman's project pilot for the Bearcat series was legendary test pilot Corky Meyer, who also had this role on the F6F Hellcat, F7F Tigercat, F9F Panther, XF10F-1 Jaguar, and the F11F Tiger series. Meyer was head of Grumman Flight Operations at Edwards Air Force Base from 1952–56. 
Another famous name is associated with the type; when asked his favorite aircraft to fly, Neil Armstrong's immediate and unequivocal answer was "Bearcat". Armstrong had flown the type in 1950 during his Navy Advanced Training, field qualifying in it at age 19.
The F8F prototypes were ordered in November 1943 and first flew on 21 August 1944, a mere nine months later. The first production aircraft was delivered in February 1945 and the first squadron was operational by 21 May, but World War II was over before the aircraft saw combat service.
Postwar, the F8F became a major U.S. Navy fighter, equipping 24 fighter squadrons. Often mentioned as one of the best-handling piston-engine fighters ever built, its performance was sufficient to outperform many early jets. Its capability for aerobatic performance is illustrated by its selection for the Navy's elite Blue Angels in 1946, who flew it until the team was temporarily disbanded in 1950 (during the Korean War). The Grumman F9F Panther and McDonnell F2H Banshee largely replaced the Bearcat in USN service, as their performance and other advantages eclipsed piston-engine fighters.
An unmodified production F8F-1 set a 1946 time-to-climb record (after a run of 115 feet) of 10,000 feet in 94 seconds. The Bearcat held this record for ten years until it was broken by a modern jet fighter (which could still not match the Bearcat's short takeoff distance).
Other nations that flew the Bearcat included the French Air Force and Royal Thai Air Force. French aircraft saw combat service in the First Indochina War as fighter-bombers in the early 1950s. Nearly 70 surviving aircraft passed to the Vietnam Air Force upon its creation in 1955.
Bearcats have long been popular in air racing. A stock Bearcat flown by Mira Slovak and sponsored by Bill Stead won the first Reno Air Race in 1964. Rare Bear, a highly-modified F8F owned by Lyle Shelton, went on to dominate the event for decades, often competing with Daryl Greenamyer, another famous racer with victories in his own Bearcat ("Conquest I") and holder of a propeller-driven aircraft world speed record in it. Rare Bear also set many performance records, including the 3 km World Speed Record for piston-driven aircraft (528.33 mph (850.26 km/h), set in 1989), and a new time-to-climb record (3,000 meters in 91.9 seconds, set in 1972, breaking the 1946 record cited above).  
A small number of Bearcats survive: approximately 11 are airworthy (several as racing aircraft), eight are restored for static display and approximately a dozen more are wrecks or restoration projects.
Darryl Greenamyer's Bearcat, "Conquest I" can be seen on exhibit at the Smithsonian National Air & Space Museum.